DE102007027687A1 - Sealing device for use in steering system or automatic gearbox of vehicle, has static form seal, which is arranged in form of a groove seal between two housings - Google Patents

Abstract

The sealing device (1) has a static form seal (7), which is arranged in the form of a groove seal between two housings (2,3) and encloses a moving component (5). The static form seal delivers a pre-selected pressure of a pressurizing medium between the sealing unit of the moving component and the static form seal in a pressure-free chamber (8) outside the housing.

Description

The The invention relates to a sealing device in a steering system or Automatic transmission of a vehicle between a first housing and a second housing, according to the preamble of the claim 1.

The DE 10 2005 018 308 A1 describes a servovalve for a hydraulic power steering having an input shaft operatively connected to a steering handle of a vehicle and having an output shaft operatively connected to a steering gear and a torsion bar seeking to hold the input shaft and output shaft relative to each other in a central position.

The Servo valve is formed as a rotary valve and consists essentially from a rotary valve, which represents a first valve element and from a coaxially arranged around the rotary valve control bush, which forms a second valve element. The rotary valve has in a conventional manner, a pressure port of the pressure side a servo pump is connected. Opens to the rotary valve also a low pressure port and two motor connections of a hydrostatic servomotor steered for steering angle adjustment Wheels of the vehicle.

Of the Rotary slide is rotatably connected to the input shaft. The tax account is rotatably connected to the output shaft. Will the rotary valve twisted relative to the control jack in one direction or the other, becomes with the servo pump between the engine connections a more or less large controllable pressure difference in the one or the other direction generated, with the result that the servomotor in one or the other direction a correspondingly large Force generated.

The Servovalve as part of a hydraulic system is in a first Housing arranged.

to Modification by the operation of the input shaft given input is that of the input shaft associated end of the torsion bar non-rotatably with the input shaft connected, but can be controlled by a backlash coupling be twisted relative to this. In particular, the tax socket relative to the output shaft or the input shaft associated end the torsion bar are rotated relative to the input shaft, including a housed in a second housing electrical Actuator with a wave gear is used, which is an adjusting sleeve drives, which acts on one end of the torsion bar.

Of the Torsion bar and the input shaft are moving parts, which protrude through the two housings. In the two cases prevail different pressure potentials by a sealing device in the form of a shaft seal between the input shaft and the sealed first housing.

at Any leakage of the rotary valve and the shaft seal could the second housing with the electric Fully pressurized actuator with pressure medium and the superposition steering would not be operational anymore.

Of the Invention is based on the object, a sealing device in To create a steering system or automatic transmission that is safe, durable Operation possible.

The Task is with a sealing device with the characteristics of Claim 1 solved.

Thereby that a static molded seal between the first and second Housing is arranged, preferably the movable member encloses with radial distance and wherein the static molded seal in the gradient of the pressure potentials between the housings the sealing device is mounted downstream of the movable component and a fluidic connection between the sealing device and The static mold seal can exist in case of any leakage and a pressure increase upstream of the static molded seal pressure means of the static seal from exceeding a predetermined Pressure in an approximately unpressurized space outside the housing are discharged without pressure medium flows from one housing into the other.

preferred Designs emerge from the dependent claims.

The static molded seal is preferably integrally formed from an elastomer and annularly formed with a smooth, annular working strip, which is biased in the axial direction of the movable member to a sealing surface of one of the two housings. The bias can be effected by a support ring in or on the static molded seal. The static molded seal is preferably inserted in a rectangular or U-shaped annular groove on an end face of a housing, wherein the depth of the annular groove can specify the bias of the static molded seal. From a fluid pressure of about 0.5 bar, it preferably opens a flow path from the shaft sealing ring via the static molded seal into an approximately pressureless or pressureless space outside the two housings. Leakage oil can be discharged into the open air. The working bar of the static molded seal closes after the pressure medium has flowed out and ver Prevents such an entry of, for example, splash water in the housing.

The Sealing device may preferably in a hydraulic power steering trained hydraulic system can be used. For example For example, the movable member may be a shaft of an electric actuator be that in addition to a manual twisting of a Valve element (rotary valve) of a steering valve, the valve element twisted in one direction or the other, which, for example straight-line running of a vehicle, in particular a commercial vehicle, can be regulated. In addition, transverse dynamic disturbance variables can be achieved such as crosswind or road inclines and / or the actual yaw angle of a vehicle according to a current steering wheel angle.

The Invention will now be closer with reference to an embodiment described and reproduced with reference to the accompanying drawings.

1

sealing

2

Casing, first

3

Casing, second

4

Plant part, hydraulic

5

component movable

6

sealing

7

Shaped seal, static

8th

Room, unpressurized

9

Task bar

10

sealing surface

11

ring groove

12

wave

13

actuator electrical

14

steering valve

15

valve element

16

rotary vane

17

Rotary valve

18

longitudinal axis

19

control connector

20

torsion bar

21

Shaft seal, first

22

Shaft seal, second

1 shows a partial longitudinal section through a sealing device on a steering valve.

In 1 is in a partial longitudinal section along its longitudinal axis 18 a steering valve 14 as a rotary valve 17 is formed, shown. The rotary valve 17 , as part 4 a hydraulic system, namely a superposition steering, is essentially a first housing 2 built, the one, with a steering handle operatively connected rotary valve 16 picks up and in a control socket 19 is arranged, to which the rotary valve 16 is limited rotatably mounted. The tax account 19 is connected to a valve output member, not shown, which serves for the displacement of a rack, not shown. The rack is connected in a conventional manner in parallel or in series with a servo cylinder together on tie rods and wheel steering with steered wheels of a commercial vehicle.

The rotary valve 16 and the tax socket 19 have control longitudinal grooves whose relative rotation to each other control a pressure medium flow for the servo cylinder.

To reset the rotary valve 16 relative to the control socket 19 serves a torsion bar 20 ,

In a second housing 3 that with the first case 2 is releasably connected, is an electrical actuator 13 arranged with a worm gear. One as a wave 12 formed component 5 of the electric actuator 13 is via a profile shaft connection with the rotary valve 16 formed valve element 15 of the steering valve 14 rotatably connected and used to enter an overlay size for the inputted by the driver on the steering handle steering torque.

To the inflow of leakage oil or pressure medium of the steering valve 14 in the case 3 of the electric actuator 13 To safely avoid is a sealing device 1 at the parting line of the two housings 2 . 3 provided, consisting of a first shaft seal 21 (sealing 6 ) between the rotary valve 17 and the first housing 2 and from another, second shaft seal 22 between the rotary valve 17 and the second housing 3 consists. Between the first shaft seal 21 and the second shaft seal 22 For example, a leakage oil flow path is provided in the first and / or second housings, the leakage oil into a static form seal 7 directs. The static molded seal 7 is formed in the embodiment shown as a one-piece annular seal of an elastomer and has a conically tapering in the radial direction edge with a task bar 9 on. The annular work bar 9 lies with axial preload on a sealing surface 10 of the second housing 3 at. The static molded seal 7 is in a rectangular ring groove 11 at the parting line of the two housings 2 . 3 in the first case 2 inserted.

The static molded seal 7 is capable of exceeding a predetermined pressure medium pressure, for example, 0.5 bar, pressure medium, which is located between the shaft seals 21 . 22 and the static molded seal 7 has accumulated after detaching the taskbar 9 from the sealing surface 10 in a depressurized room 8th on the outside of the housing of the steering valve 14 leave. The static molded seal 7 Prevents ingress of splashing water into the housing interior of the two housings.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102005018308 A1 [0002]

Claims (11)

Sealing device in a steering system or automatic transmission of a vehicle between a first housing ( 2 ) and a second housing ( 3 ), wherein at least in one housing ( 2 . 3 ) a part ( 4 ) is arranged a hydraulic system and from a housing ( 2 . 3 ) a movable component ( 5 ) in the other housing ( 2 . 3 ) protrudes, wherein the movable component ( 5 ) against the housing ( 2 . 3 ) with a sealing device ( 6 ) and a different pressure potential of pressure medium in the first housing ( 2 ) and the second housing ( 3 ), characterized in that a static molded seal ( 7 ) in the manner of a groove seal between the first and second housings ( 2 . 3 ) is arranged, which the movable component ( 5 ) and the static molded seal ( 7 ) from a prescribable pressure of the pressure medium between the sealing device ( 6 ) of the movable component ( 5 ) and the static molded seal ( 7 ) Pressure medium in an approximately depressurized space ( 8th ) outside the housing ( 2 . 3 ). Sealing device according to claim 1, characterized in that the static molded seal ( 7 ) a soft touch seal with a smooth, annular work bar ( 9 ). Sealing device according to one of claims 1 or 2, characterized in that the static molded seal ( 7 ) a bias on her taskbar ( 9 ). Sealing device according to claim 3, characterized in that the bias by a support ring in the static molded seal ( 7 ) is effected. 5. Sealing device according to one of claims 3 or 4, characterized in that the annular working strip ( 9 ) in the axial direction of the movable component ( 5 ) on a sealing surface ( 10 ) of a housing ( 2 . 3 ) is biased. Sealing device according to one of claims 1 to 5, characterized in that the static molded seal ( 7 ) in a U-shaped annular groove ( 11 ) of a housing ( 2 . 3 ) is arranged. Sealing device according to one of claims 1 to 6, characterized in that the static molded seal ( 7 ) at a fluid pressure of about 0.5 bar and more pressure medium in the non-pressurized space ( 8th ). Sealing device according to one of claims 1 to 7, characterized in that the movable component ( 5 ) a wave ( 12 ) of an electric actuator ( 13 ). Sealing device according to claim 8, characterized in that in the second housing ( 3 ) a steering valve ( 14 ) is arranged to control the pressure medium of a hydrostatic actuator of a steering system. Sealing device according to claim 9, characterized in that the electric actuator ( 13 ) over the wave ( 12 ) a valve element ( 15 ) of the steering valve ( 14 ) and is an actuator for a superposition steering. Sealing device according to claim 10, characterized in that the valve element ( 15 ) a rotary valve ( 16 ) a rotary valve ( 17 ). Sealing device according to one of claims 1 to 11, characterized in that the sealing device ( 1 ) Is part of a steering system for a commercial vehicle.